Next, let \(s\)  and \(\gamma \)  be parameters that we will specify below. Proceeding as in [1]}, we define
\(B = \Big \lbrace \frac{a_1-a_2}{a_3-a_4}\colon a_i\in A_1,\ |a_3-a_4|>\delta ^\gamma \Big \rbrace .\) 
